Theoretical study of Ce2+ cubic centres in alkaline earth fluoride crystals

• Ab inito study of Ce2+ impurity centres in alkaline earth fluoride crystals.
• Calculated Ce2+ ground state in CaF2 and SrF2 is predominantly 4f15d1 singlet.
• Calculated absorption spectra are in good agreement width experimental data.

In this paper we present theoretical study of Ce2+ impurity centres in alkaline earth fluoride crystals (CaF2, SrF2). Only cubic configurations of centres were considered. Electronic levels and related properties were studied using CASSCF/CASPT2 approach within embedded-cluster formalism including scalar relativistic corrections and spin-orbital interaction. Calculated absorption spectra for Ce2+ in CaF2 and SrF2 are in good agreement with experimental data. For both crystals the ground state of Ce2+ ion has predominantly 4f15d1 singlet character.